Method and device for operating an indicating unit on a working machine

ABSTRACT

Working machines are often used in industry for manufacturing purposes and for logicistical tasks. Said working machines perform to a certain extent predictable but often exclusively repetitive tasks. It is often difficult for people in the vicinity of the working machines to understand the regular working process of such a working machine. It is also difficult to recognise automatically performed modifications of said working process. The invention makes it possible to look ahead and point to objects within the working range of the working machine in a specific manner. As a result, persons located within the vicinity of the working machine and/or other working machines can intervene in a timely manner in the working process and can, for example, eliminate or prevent any disruptions occurring therein. The invention makes it possible to indicate the working process of the working machine per se in a specific manner in the vicinity thereof. By projecting patterns onto objects, people can very quickly understand which objects and working machines are currently involved in the working process and which steps should be subsequently carried out. Interactions between human beings and machines and between cooperating working machines are thus simplified to a significant extent.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for operation of a pointing unit on aprocess machine, and to a pointing unit on a process machine, as claimedin the precharacterizing clauses of patent claims 1 and 16.

2. Related Art of the Invention

Process machines are frequently used in industry for manufacturingpurposes and for logistics tasks. The range in this case extends frommachines with fixed programs via unmanned transport systems on tracks toautonomous systems which automatically orient themselves with respect totheir surrounding area. In the past, process machines such as thesehave, frequently, however, carried out only repetitive tasks, which canbe predicted within limits. In this case, there is no direct interactionwith people who are involved in the process sequence. It is thereforeoften very difficult for people who are located in the immediatevicinity of the process machines only at times to become involved in theregular process sequence of a process machine. It is also difficult toidentify changes carried out automatically to the process sequence and,for example, a change to the process sequence may be required owing tounexpected disturbances.

The Japanese patent application with the publication number JP2000089163 discloses a pointing appliance by means of which it ispossible to point to sought objects which are contained in videosequences. An object is in this case selected by means of a search termwhich is predetermined by the user. The search term can be entered inthe pointing appliance by means of voice control, for example. In thiscase, an image which contains object hypotheses is recorded by means ofan image recording unit. The object hypotheses are checked by a checkingunit to determine whether they match a previously entered search term.The check can in turn be carried out by means of text identification.The direction in which the sought object is located within the videosequence is calculated by means of a further unit, based on the resultof the check. Finally, a laser beam is emitted by means of a laser inthe calculated direction, in order to indicate the sought object withinthe video sequence.

Stationary process machines which interact with people and indicateprocess sequences are known, and, by way of example, the Japanese patentapplication with the publication number JP 11085237 proposes a robot armwhich extends to people and objects. The operating range of the robotarm is in this case defined in a fixed form and corresponds to apredetermined size, since this relates to a system which is installed ina fixed position. The future movement sequence of the robot arm as wellas the intended position at which an object is intended to be passed tothe person are projected by means of a projector for movementmonitoring, based on a three-dimensional geometric data model. Theprojection is in this case produced 2-dimensionally on the workingsurface of the working area.

The US document with the patent number U.S. Pat. No. 4,714,399 proposesan automatically controlled, unmanned vehicle which is equipped with amounting element for holding loads. The mounting element can be openedand closed selectively and is equipped with a number of sensors. Thesensors are used on the one hand in order to monitor the load to betransported and surfaces located in the vicinity of the load, and on theother hand to control the movement of the mounting elementautomatically. However, one of these sensors at the same time alsomonitors the area in front of the vehicle, by which means it is possibleto automatically identify obstructions which are in the way and, ifnecessary, to stop the vehicle.

Autonomous process machines are also known which orient themselvesautomatically with respect to their environment. The European patentwith the patent number EP0800129 B1 describes an industrial truck whichcan be operated manually or automatically, by selection. The industrialtruck has its own on-board monitoring system in order that it cannavigate freely within the area. Depending on the predeterminedtransport task and the identified vehicle position within the area, themonitoring system can use the stored routes to find a suitable path, andto guide the industrial truck along this path. In order to manipulatepallets or loads, it is not necessary to arrange them previously exactlyat a specific position within the area, since the monitoring systemdetects the position of the pallet, and appropriately adapts themovement sequence of the industrial truck. The industrial truck is alsoprovided with a means which makes it possible to brake the vehicle whenpeople or obstructions are present.

A driverless transport system is described in the Proceedings of theinternational symposium on automotive technology and automation (ISATA),Florence, May 20-24, 1991, No. Symp 24, May 20, 1991, pages 615-622,Propert P.J. et al.: “Sensor based capabilities in guided vehicles forfactory automation”, which is provided with additional devices in orderto allow further operation of the driverless transport system in theevent of disturbances on a predetermined or selected route, for examplea route which is partially or completely blocked by an obstruction. Forthis purpose, the driverless transport system is provided with sensorsand control devices, by means of which it is possible to detect anobstruction on the predetermined or selected route and, if appropriate,to automatically reorganize or replan the route. Changes to the regularprocess sequence of the process machine are not communicated to peoplewho are located in the vicinity of the process machine.

SUMMARY OF THE INVENTION

The invention is based on the object of providing a novel method foroperation of a pointing unit on a process machine, as well as a processmachine having a pointing device for carrying out the method as claimedin the precharacterizing clauses of patent claims 1 and 16, which makesit possible to communicate with people and/or with other processmachines.

According to the invention, the object is achieved by a method and apointing unit having the features of patent claims 1 and 16.Advantageous refinements and developments of the invention are describedin the dependent claims.

According to the invention, a process machine is operated in conjunctionwith sensors. In this case, the sensors are used to dynamically recordthe area surrounding the process machine, with object identificationbeing carried out by means of a computer unit on the basis of thedetection of the surrounding area. Obstructions detected during theobject identification in the working area of the process machine aretaken into account and cause the process machine to be switched off orthe process sequence to be reorganized/replanned. The process machine isnow provided in an inventive manner with a pointing unit which is usedfor setting up optical communication between the process machine and/orother process machines. For this purpose, the pointing unit comprises anillumination unit, by means of which patterns are deliberately projectedonto objects which are located in the area surrounding the processmachine, for optical communication.

The invention for the first time makes it possible to deliberatelyindicate objects in advance in the working area of the process machine.People and/or other process machines which are located in the areasurrounding the process machine can thus intervene in the processsequence in good time and, by way of example, can correct or evenprevent any disturbances. The invention also makes it possible toindicate the process sequence of the process machine per se,deliberately in its surrounding area. The projection of patterns ontoobjects allows people to tell very quickly which objects and otherprocess machines are currently involved in the process sequence and whatsteps should be carried out next. This considerably simplifies not onlyinteractions between people and the process machine, but also betweencooperating process machines.

The objects may be obstructions which are located in the working area ofthe process machine. The advanced indication of obstructions means thatit is not absolutely essential to switch off the process machineimmediately. This advanced indication of obstructions also means that itis not essential to reorganize/replan the process sequence. For example,people or other process machines can still remove obstructions from theworking area in good time before the process machine reactsautomatically to them and, for example, reorganizes the processsequence. It is also feasible for the objects to be objects which arerelated to the process sequence of the process machine. Advancedindication of the next objects to be manipulated allows people or otherprocess machines to interact with the process machine in a simplemanner. For example, someone can hand a process machine precisely thatobject which is indicated by it, and this also applies in acorresponding manner to other process machines; another process machine,for example, produces an object exactly at the position indicated by theprocess machine, and this also applies in a corresponding manner topeople.

In one advantageous embodiment of the invention, it is also feasible touse a laser beam for the projection of patterns. Galvanometer scannersare particularly suitable for this purpose, and allow the laser beam tobe projected very quickly and with very high position accuracy.Galvanometer scanners can be controlled by means of acomputer-controlled deflection unit, so that the patterns to beprojected may have any desired shape.

It is also possible by the alternative use of an illumination unit whichoperates in conjunction with an array of optical lenses to projectpatterns with any desired extent onto the objects. By way of example, anillumination means having a fiber-coupled lens array may be used as theoptical illumination unit. In the same way, it is also feasible to useillumination means which are known from automobile engineering for thepurposes of the invention, in which the shape and intensity of the lightbeam of a spotlight or headlight can be varied. Such illumination isintended to be used to avoid dazzling the drivers of oncoming vehicles,and to illuminate the curves better when turning. The internationalpatent application WO 98/54030 proposes various forms for theconfiguration of such illumination means, based on the example of avehicle spotlight or headlight.

It is also feasible for the illumination unit to be an illumination unitwhich is already intended for other purposes in conjunction with theprocess machine. For example, process machines frequently useillumination sources to indicate the direction in which they aretraveling. The use of the same illumination source for differentpurposes on the one hand saves costs and on the other hand consumes lesselectrical power, which is particularly advantageous in the case ofprocess machines powered by rechargeable batteries.

The method according to the invention allows patterns with any desiredshapes to be projected in a general form. However, it has been found tobe particularly advantageous to project patterns which are in this casein the form of defined symbolic representations. Geometric shapes suchas circles, triangles etc. are particularly suitable, by way of example,and it is also feasible to project script characters or numbers. It isthus possible to associate a unique pattern with each process machinefor projection. People or other process machines can thus more easilyassociate the projected patterns with that particular process machine.

The unique association of the patterns with a process machine may,however, also be achieved by the use of different blinking frequenciesfor projection.

It is also feasible for the patterns to be projected to extendcompletely over that surface of the object which is visible from theviewing direction of the process machine, and thus to be identified at aglance.

In addition, it has also been proven for the patterns to be projectedonly onto a portion of the surface of the object which is visible fromthe viewing direction of the process machine. Specific information canthus be projected at positions being looked for (for example the leftupper corner) on the object surface.

In a further advantageous refinement of the invention, it has beenproven for the patterns to be projected in a blinking form. Particularlyin the case of very bright objects or structured projection surfaces,blinking projection of the patterns can be seen more clearly thancontinuous projection against the background. A blinking representationof a pattern may, however, also advantageously be linked to a particularevent occurring in the area surrounding the process machine. Forexample, when the rechargeable battery in a process machine is virtuallydischarged. The blinking frequency can also be varied dynamically. Forexample, once an obstruction has been identified in the processsequence, it is possible to initially illuminate this continuously. Ifthe obstruction is not removed, the process machine then starts toreplan the process sequence. Until the amended process sequence isactually continued, the pattern is represented using an increasingblinking frequency. A means which allows the respective light source tobe operated in a pulsed form can be provided for this purpose, dependingon the chosen light source.

It is also feasible to automatically vary the intensity of theillumination on the basis of changing environmental conditions. A changein the environmental conditions can indicate that the backgroundlighting resulting from daylight is changing. However, external lightsources which vary on the basis of production processes (for example inthe case of welding), or changing light sources on other processmachines can be compensated for well by automatically varying theintensity of the illumination. A further significant point is a changein the condition of the projection surface, so that the color or thestructure of the surface to which the pointing unit is pointing maydiffer at different points. Such differences can be compensated forparticularly well by automatic variation of the illumination intensity.In this context, a further means can be provided by means of which suchchanges in the environmental conditions can be detected, in particular,with cameras or photo-elements being particularly suitable for thispurpose.

In a further advantageous refinement of the invention, light atdifferent wavelengths is used for illumination. If two or moreautonomous process machines are working in the same area, then eachprocess machine may be allocated a separate wavelength, in order todistinguish better between them. In this case, the wavelengths should bechosen such that their difference is ideally more than 50 nm so that thewavelength band which is visible to a human observer can be subdividedinto a large number of colors which can still be clearly distinguished.

In particular, it has been proven for the illumination to use light inthe non-visible wavelength range, in particular in the infrared. Thismakes it possible reliably indicate the process sequences of differentautonomous systems, thus minimizing the influences of the environmentallighting. For this purpose, each autonomous system is preferablyallocated one fixed wavelength in the infrared band. The wavelengths forthe respective machines may in this case be very close to one another,so that one wavelength can be uniquely allocated for a large number ofprocess machines.

It has also been proven for the illumination source to be switched onand off in order to illuminate the working area, taking account ofenvironmental conditions. Particularly when no people or any otherautonomous systems are located in the area surrounding the processmachine, it is worthwhile switching off the illumination means used forprojection, thus saving energy.

The illumination means which have been mentioned in conjunction with thepointing unit in some cases have restricted emission angles and can thusnot emit light over the entire area around a process machine. In afurther advantageous refinement of the invention, an additional means istherefore provided, in order to automatically change the position and/orthe orientation of the illumination unit on the process machine. For thefirst time, this makes it possible to cover the entire area around aprocess machine, even when using illumination sources with narrow beams.

The invention can also be used in a particularly advantageous manner inconjunction with mobile process machines, in particular driverlesstransport systems. This allows interactions between people and a processmachine as well as between cooperating process machines to beconsiderably simplified even in complex industrial scenarios.

1. A method for operation of a process machine in conjunction withsensors, comprising: dynamically recording the area surrounding theprocess machine with object identification being carried out by means ofa computer unit, switching off the process machine or reorganizing aprocess sequence by taking obstructions detected during the objectidentification in the working area of the process machine into account,wherein optical communication is set up by means of a pointing unit,which is fitted to the process machine, between the process machine andpeople and/or other process machines, wherein patterns are deliberatelyprojected onto objects located in the area surrounding the processmachine by means of an illumination unit, for optical communication. 2.The method as claimed in claim 1, wherein the objects are obstructionsin the working area of the process machine, which should be removed bypeople and/or other process machines.
 3. The method as claimed in claim1, wherein the objects are objects which are related to the processsequence of the process machine, and which should be manipulated bypeople and/or other process machines.
 4. The method as claimed in claim1, wherein a laser beam is used as the illumination unit for projectionof patterns onto objects, and the laser beam is controlled by acomputer-controlled deflection unit.
 5. The method as claimed in claim1, wherein an illumination unit which operates in conjunction with anarray of adjustable optical lenses is used for projection of patternsonto objects.
 6. The method as claimed in claim 1 wherein theillumination unit is an illumination source which is already providedfor other purposes in conjunction with the process machine.
 7. Themethod as claimed in claim 1 wherein the projected pattern correspondsto a defined symbolic representation.
 8. The method as claimed in claim1 wherein the projected pattern extends completely over that surface ofthe object which can be seen from the viewing direction of the processmachine.
 9. The method as claimed in claim 1 wherein the pattern extendsonly over a portion of that surface of the object which can be seen fromthe viewing direction of the process machine.
 10. The method as claimedin claim 1 wherein the pattern is projected in a blinking form.
 11. Themethod as claimed in claim 1 wherein the intensity of the illuminationis varied automatically on the basis of changing environmentalconditions.
 12. The method as claimed in claim 1 wherein light atdifferent wavelengths is used for illumination.
 13. The method asclaimed in claim 1 wherein light in the non-visible wavelength band, inparticular in the infrared, is used for illumination.
 14. The method asclaimed in claim 1 wherein the illumination source is switched on andoff depending on the environmental conditions.
 15. (canceled)
 16. Aprocess machine, comprising sensors by means of which data relating tothe surrounding area is recorded dynamically during operation of theprocess machine, a computer unit by means of which object identificationis carried out on the basis of the data relating to the surroundingarea, a control unit and further means are provided, in order to switchoff, reorganize or replan the process sequence taking into accountobstructions detected in the working area of the process machine,wherein the process machine is provided with a pointing unit forcommunication purposes, with the pointing unit having an illuminationunit, by means of which communication is carried out between the processmachine and people and/or other process machines, and by means of whichpatterns are deliberately projected onto objects which are located inthe area surrounding the process machine.
 17. The process machine asclaimed in claim 16, wherein a galvanometer scanner is provided as theoptical illumination unit.
 18. The process machine as claimed in claim16, wherein an illumination means which comprises a fiber-coupled lensarray is provided as the optical illumination unit.
 19. The processmachine as claimed in claim 16, wherein the optical illumination unit isalready provided for other purposes in conjunction with the processmachine.
 20. The process machine as claimed in claim 16, wherein a meansis provided in order to operate the illumination means in a pulsed form.21. The process machine as claimed in claim 16, wherein an additionalmeans is provided in order to automatically change the position and/orthe orientation of the illumination unit on the process machine. 22.(canceled)